What is bioretention soil used for?

Bioretention areas (also referred to as bioretention cells or rain gardens) use soil, plants and microbes to treat stormwater before it is infiltrated or discharged. Bioretention areas are shallow depressions filled with sandy soil, topped with a thick layer of mulch, and planted with dense vegetation.

What are bioretention areas?

Bioretention areas are shallow landscaped depressions which are typically under drained and rely on engineered soils, enhanced vegetation and filtration to remove pollution and reduce runoff downstream.

What is the difference between Bioswale and bioretention?

Bioswales, which are wet or dry swales made out of grass, rocks, and other types of vegetation, must be sloped to move water through the system in an efficient manner. Bioretention ponds are depressed vegetated areas that capture and store stormwater runoff and can work in combination with bioswales.

How does a bioretention system work?

A bioretention system consists of a soil bed planted with suitable non-invasive (preferably native) vegetation. Vegetation in the soil planting bed provides uptake of pollutants and runoff and helps maintain the pores and associated infiltration rates of the soil in the bed.

What do bioretention basins do?

A bioretention basin is a bioretention system that provides efficient treatment of stormwater through fine filtration, extended detention and some biological uptake. Purpose: Removal of fine and coarse sediments.

What benefit does a bioretention garden provide?

Rain gardens can be beneficial to neighborhood landscapes by absorbing stormwater runoff and allowing the runoff to percolate through the soil media. This process helps remove the pollutants and slow down runoff.

What is bioretention media?

Bioretention Soil Media (BSM) is a formulated soil mixture that filters pollutants from stormwater, retains moisture, and supports healthy vegetation. It is used in LID BMPs including Bioretention, Biofiltration with Partial Infiltration, and Biofiltration with No Infiltration.

How do Bioswales help the environment?

A bioswale is one way to protect our surface waters by decreasing stormwater runoff. It is a gently sloping vegetative swale designed to slow and reduce stormwater runoff while filtering out pollutants. The benefits of a bioswale on water quality include: Protects local waterways from stormwater pollutants.

How do you maintain a Bioswale?

Remove weeds and invasive plants. Remove any trash that has washed into the bioretention area or the inlet channels or pipes. Check the facility a few days after a rain storm to make sure that there is no standing water after 4 days. Cut back dead stems of herbaceous plants in March and remove from the facility.

What is a bioretention wall?

Bioretention planters are stormwater infiltration cells constructed with walled vertical sides, a flat bottom area, and a large surface capacity to capture, treat, and manage stormwater runoff from the street.

What is a wet detention pond?

A common stormwater treatment system is called a wet detention pond. Wet detention ponds contain water at all times and serve a dual purpose. They treat stormwater runoff to protect our creeks and streams, and during severe storms, they help prevent flooding.

Which is the best definition of bioretention?

Bioretention Definition. Practices that capture and store stormwater runoff and pass it through a filter bed of engineered soil media comprised of sand, soil, and organic matter. Filtered runoff may be collected and returned to the conveyance system, or allowed to infiltrate into the soil. Design variants include:

When do you need an underdrain for bioretention?

Underdrains may be required if the measured permeability of the underlying soils is less than 0.5 in./hr. When designing a bioretention practice, designers should verify soil permeability by using the on-site soil investigation methods provided in Appendix P. Impermeable soils will require an underdrain.

Which is better a bioretention basin or a swale?

In general, a bioretention basin has a flat bottom while a bioretention swale may have sloping bottom. Runoff storage depths above the soil bed surface are typically shallow. The TSS removal rate for bioretention systems is 80 or 90 percent, depending upon the thickness of the soil planting bed and the type of vegetation grown in the bed. Purpose

How is SOD used in a bioretention system?

If the bioretention cell has sod specified for its cover (as opposed to tree/shrub/mulch systems), the sod must be either 1) grown on sandy underlying soils or 2) be washed sod. Washed sod has had all soil removed from the roots, which prevents the sod layer from restricting infiltration into the underlying media.